How to keep a toddler busy

Olivia is a busy girl.  I don't know if she's any busier than other kids her age, but toddlers have notoriously short attention spans and Olivia gets bored doing the same things over and over.  I polled my friends for ideas for inexpensive entertainment and Elizabeth gave me this idea.  Put rice in a box and have Olivia bury objects in it.  I got some farm animal miniatures at Michaels so we can make it more interesting with animal sounds, and there's a cup for scooping rice (and hopefully dumping it back in the box).  We do this on the porch so it's out of the sun but I don't have to vacuum every time.

Another idea from Elizabeth was to let Olivia paint the sidewalk with a paintbrush and water.  Zero cleanup, and when the paintbrush is inside (and dry) it's still fun for her to "paint" things.

Livi also enjoys pouring things from one container to another in the rice bin, sandbox, bathtub, and now of dry cereal or water from cup to cup.  She has a little table and chairs for a play surface on her level, and Riley helps with the cleanup.  Any more under-two entertainment ideas from the peanut gallery?  I am saving things like finger paints and play-doh for when she's a little older because of the enjoyment-to-cleanup ratio.

New words for Olivia:
Where are you? (Whyou, not to be confused with Wy-ee which is Riley)
I see you
shoe (previously soss)
rock
hot
please (peesh?)
baby
Lyla (Wy-wa)
Ellie (Eh-ee)

I do interval training, so when Olivia is in the stroller and I start running she says, "Wheeeeeeeee," like that little piggy.